[pianotech] Steinway A Bass String Rescaling

[Ron Overs]

>My point was, and is, that we don't hear the inharmonicity in the 
>pianos. We hear tension, Z, and partials mix our choice of core 
>wire, tension, and break% gives. Inharmonicity comes in when you're 
>trying to tune across a transition with a big mismatch.

I agree Ron N that the poor transition of inharmonicity and Z across 
the bass/treble break is perhaps the most obvious problem with many 
OEM scales. The usual tunability mess that is created when a designer 
decides to use covered bi-chords on the last few notes on the long 
bridge as a band aid fix for plummeting string tensions in the 
hockey-stick area is also one of my pet hates. Why design a piano 
with such an obviously poor work-around when a better solution would 
be to take a dash of courage, and design the piano with the break 
further up the scale, where it should have been in the first place?

However, I believe that if inharmonicity is high enough it does 
effect our ability to easily determine the pitch of a note in the low 
bass, where in some scales the inharmonicity can be undesirably high. 
The obvious example of this would be a comparison between a piano 
with a very short bass scale and any concert instrument, when 
comparing the lowest minor third interval C to A on the keyboard. 
When listening to this interval on a long-bass scale the minor third 
will be well defined. But the same test on the shorter scaled bass 
will sound nothing like a real minor third. The higher inharmonicity 
of the short string scale will result in such pitch deviation between 
the fundamental frequency and the upper partials, that the identity 
of pitch will become a murky matter.

Even in a rescaled D, pitch identity on the low bass can be improved. 
We had the opportunity to compare our modified model D bass scale to 
an OEM iteration first hand between 1993 to 1988. Of the two 
performance Ds at the ABC, one had our modified scale while the other 
remained factory standard. The piano with the OEM bass had been 
restrung also, but we decided to leave its string scale as factory 
standard, to cater for those pianists who might have had a preference 
for the standard bass tone. The pitch identity improvement of the 
lower inharmonicity scale was noticeable. This was noteworthy because 
the high inharmonicity scale was only about 3 cents sharp on the 
double octave harmonic of the low A, while the improved scale was 
under 2 cents on this note, and we could hear an improvement in the 
perceived pitch identity.

Ron O.
-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
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Web http://overspianos.com.au
mailto:ron at overspianos.com.au
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